1. Field of the Invention
This invention relates to devices for installing and removing power bridges and, more specifically, to a power bridge installation/removal system and a method of utilizing the system.
2. Background Information
Excitation control systems utilize a power bridge to convert alternating current to a direct current. The power bridge is generally block shaped having an external bus assembly disposed at the top. The power bridge is about thirty-two by twenty-seven by forty-six inches and may weigh up to 1000 pounds. Typically, the power bridge is disposed in an enclosure having a rugged frame. The power bridge is usually disposed on a raised platform located within the enclosure. The platform is, typically, more than a foot above the bottom of the enclosure. In the prior art, the power bridge merely rested on the platform and did not include any installation or removal devices. As such, the installation or removal of the bulky power bridge was a time and labor intensive event requiring a technician to use an overhead winch to lift the power bridge and brute force to move the power bridge into, or out of, the enclosure.
There is, therefore, a need for an installation/removal system for a power bridge to reduce the time and effort required to install/remove a power bridge.
There is a further need for an installation/removal system for a power bridge that can be adapted to power bridge and enclosures presently in use.
There is a further need for an installation/removal system for a power bridge that can be adapted to act as a transport device for a power bridge.
These needs, and others, are met by the present invention that provides a power bridge removal system having a roller assembly with a plurality of wheels and which encloses the power bridge, a power bridge enclosure assembly having a set of wheel tracks structured to cooperate with the roller assembly, and a dolly assembly structured to securely mate with the power bridge enclosure and which can be adapted to be a transport means. The roller assembly includes, preferably, four wheels, disposed in pairs on two opposite sides of the assembly. The roller assembly wheels travel on the two wheel tracks that are part of the enclosure. Preferably, the wheels are disposed at the bottom of the power bridge roller assembly and the wheel tracks are structured to support the power bridge from below. The dolly includes a frame assembly, a lifting device, an interchangeable connector device, and a plurality of wheels. The lifting device is coupled to the dolly frame assembly and structured to move a connector device vertically. The connector device is structured to be coupled to various work platforms, for example, a skid table or lifting yoke. The skid table includes a generally horizontal flat plate with an upwardly open V-flange on one edge. The V-flange is structured to connect to an engagement member, typically a vertical planar member, on the power bridge enclosure.
In operation, the dolly assembly is used to remove the power bridge from, or install said power bridge in, the enclosure assembly. To do this, the work platform is disposed adjacent to the enclosure assembly and then coupled to the roller assembly. That is, the user prepares the enclosure and power bridge by removing access panels and disconnecting the power bridge bus from any lines so that the power bridge is free to be removed. At this point the power bridge is disposed within the roller assembly and the roller assembly is resting on the wheel tracks. The dolly, with the skid table assembly attachment, is then moved adjacent to the enclosure. The lifting means is actuated to lift the skid table assembly. As the skid table assembly is raised, the V-flange engages the engagement member on the enclosure. The V-flange is sized and positioned so that when the engagement member moves into the V-flange, the skid table assembly plate is drawn immediately adjacent to, and level with, the wheel tracks. The power bridge is then removed from the enclosure by rolling the roller assembly containing the power bridge onto the skid table assembly. The skid table assembly, preferably, includes a wheel lock to secure the power bridge. Once the wheel lock is engaged, and the roller assembly is coupled to the skid table assembly, the skid table assembly is lowered until the V-flange is disengaged from the engagement member and the dolly assembly may be moved away from the enclosure. If required, the skid table assembly can be disposed on the floor so the lifting device may be decoupled from the skid table assembly and coupled to a lifting yoke. The lifting yoke is structured to be coupled to the power bridge at yoke brackets located on the sides of the power bridge housing. Thus, if needed, the power bridge may be lifted off the skid table assembly and deposited on another surface, e.g. a shipping pallet or worktable. Installation of a power bridge is, essentially, the reverse of the removal procedure.